WO 02/50528 A1 discloses a gas sensor system integrated on a single chip, including a microsensor with a microheater of essentially round, elliptic or polygonal structure and electronic circuits. The microsensor is arranged on a thermally isolated membrane.
U.S. Pat. No. 7,495,300 B2 discloses a gas-sensing semiconductor device on silicon, comprising a resistive heater made of tungsten embedded in a thin silicon oxide layer that is formed over a recess of the silicon substrate. The device can be monolithically integrated with a circuitry using a CMOS process.
WO 2010/006916 A1 discloses a semiconductor device with a through-silicon via. A connection pad is arranged in the insulation layer of an SOI substrate, and a contact hole is formed in the silicon above the pad. A metallization is applied to the pad and to the sidewall of the hole and connects the pad with a top metal.